Patent application title: Tube Device for a Motor Vehicle Air Filter System and Related Method of Assembly

Abstract:

The invention relates to a motor vehicle air filter system with pipe
elements for feed and discharge of an air flow, particularly for an
internal combustion engine. To remove water which is filtered out of the
air flow, under the bottom of the housing of the air filter a tube
element is attached. Since this assembly region is poorly accessible,
there is the risk that the tube element will be kinked or pinched during
installation and thus water cannot properly drain out. In order to enable
smooth and reliable assembly of the tube element, the tube element
according to the invention is attached to the pipe element by means of
carrier elements. In the assembly of the pipe element the tube element is
automatically located at the proper position in the installation space.
Here it is protected against kinking by its connection to the pipe
element.

Claims:

1-5. (canceled)

6. A device for draining liquid from the housing of an air filter of a
motor vehicle, having a conduit connected to an air outlet thereof and a
liquid drain outlet, comprising:a drainage conduit having an inlet end
connectable to said liquid drain outlet and an outlet end;means for
supporting a portion of said drainage conduit on said air conduit;
andmeans incorporated in said drainage conduit for conveying liquid
therethrough while precluding the passage of a gas therethrough.

7. A device according to claim 6 wherein said drainage conduit comprises a
rigid tube.

8. A device according to claim 6 wherein said drainage conduit comprises a
flexible tube.

9. A device according to claim 6 wherein said supporting means comprises
at least one clip to which said conduit may be attached.

10. A device according to claim 6 wherein said means incorporated in said
drainage conduit means comprises a one-way valve allowing the passage of
liquid therethrough.

11. A device according to claim 6 wherein said means incorporated in said
drainage conduit comprises said drainage having a first portion thereof
bent in a first direction and a second portion thereof spaced from said
second portion thereof, bent in a second direction opposite of said first
direction, providing a section of said drainage conduit holding a body of
liquid conducted therethrough forming a gas passage blockage.

12. A device according to claim 11 wherein said first, second and
intermediate portions of said drainage conduit are provided with air
s-shaped configuration.

13. A device according to claim 12 wherein said drainage conduit comprises
a flexible tube and said supporting means is positioned on said air
conduit to impart an s-shaped configuration upon said tube being affixed
thereto.

14. A method of providing the drainage of a liquid from an air filter of a
motor vehicle, provided with an air outtake conduit and a liquid drainage
outlet, while precluding the inlet of gas through said liquid drainage
outlet, comprising:providing a drainage tube having a first portion
curved in a first direction, a second portion spaced from said first
portion and curved in a direction opposite of said first
direction;attaching a first end of said tube to said liquid drainage
outlet; andsupporting said tube in said air outtable conduit.

Description:

[0001]The invention relates to a motor vehicle air filter system,
particularly for an internal combustion engine, with an air line and
water drain hose for removing the moisture collected in the air filter.
The invention also includes a method for assembly of the motor vehicle
air filter system.

BACKGROUND OF THE INVENTION

[0002]Motor vehicle air filter systems are used to remove impurities such
as sand particles and water from the air which is required by an internal
combustion engine. The intaken air is routed by way of an inlet tube into
the housing of an air filter where it first sheds larger particles and
water droplets. The air which has been precleaned in this way is then
intaken through a filter element and travels by way of an outlet tube to
the internal combustion engine. Both the air filter housing and also the
inlet and outlet tube consist of relatively stiff components in order to
withstand the negative pressure generated within the air filter system by
the suction action of the internal combustion engine.

[0003]The water which is formed in the filtration of air must be removed
from the air filter housing against this negative pressure. For this
purpose it is brought together in a collecting region on the bottom of
the housing. In the collecting region there is a drain which, however, is
closed by a valve to prevent air from flowing into the housing through
the drain due to the negative pressure which prevails in the filter
housing. With a rising water level in the collecting region, i.e., with
increasing geodetic height of the water column located over the valve,
the water pressure which acts on the valve of the drain rises until it
finally equalizes the negative pressure and the valve is pushed open.

[0004]The water which is then running out is routed by way of a drain hose
underneath the filter housing in the engine compartment into a region
where it can freely drip out. It is also possible to arrange the valve on
the exit end of the hose. This results in that the water is collected
within the hose and thus a separate collecting region on the bottom of
the housing can be dispensed with. The water collecting in the
comparatively narrow tube also ensures that the water does not slosh as
the motor vehicle is driving, by which splash water could be thrown onto
the filter element of the air filter.

[0005]Instead of a valve for preventing the inflow of air through the
drain hose, according to DE 199 42 503 A1 the drain hose is installed in
the form of a loop, or meandering. In the resulting turns of the drain
hose, according to the siphon principle there is always a minimum amount
of water which is moved due to the negative pressure in the filter
housing within the drain hose, but which prevents entry of air through
the drain hose into the filter housing as in the case of the valve.
However, this form of air sealing presupposes a relatively small cross
section of the drain hose, since otherwise air bubbles could rise through
the water column which has been displaced due to the negative pressure in
the drain hose and for this reason the desired sealing function would not
be achieved.

[0006]Since the drain hose is always attached to the bottom of the filter
housing, in the production or repair of a motor vehicle the problem is
that the drain of the air filter housing is only poorly accessible for a
mechanic, since the air filter has already been installed in the engine
compartment of the motor vehicle. Thus, there is the risk that the drain
hose will be kinked or pinched between other components in assembly such
that water can no longer drain out of the filter housing by way of the
drain hose. Due to the unfavorable location of the connection for the
drain hose, after assembly it is also difficult to check the proper
position of the drain hose under the air filter.

[0007]Therefore, the object of this invention is to enable smooth assembly
of a drain hose for the collected liquid for a motor vehicle air filter
system and thus to ensure proper alignment of the hose.

SUMMARY OF THE INVENTION

[0008]According to the invention, thus a tube element for water drainage
is attached by way of at least one carrier element to a pipe element
which is used for routing an air flow. The tube element in one embodiment
of the invention is at least partially surrounded by at least one carrier
element, i.e., the carrier element laterally surrounds the tube element.
The openings on the two ends of the tube element are thus not covered by
the carrier element. Suitable carrier elements can be, for example, cable
ties or devices for snapping-in cables and hoses which are also referred
to as clips or clip elements. If the carrier elements surround the tube
element completely, for example along the periphery of the tube element,
the coupling of the tube element to the pipe element is especially
strong. This is also achieved in another embodiment of the invention by
at least one carrier element and the tube element being materially joined
to one another. This is effected preferably by injecting the carrier
element onto the tube element.

[0009]The tube element can also be, in addition to a simple hose, a
suction hose in which peripheral support elements ensure that the hose
does not deform by the action of small forces to such a degree that it is
closed. Stiffer elements, such as a flexible tube, for example of
plastic, a corrugated hose or even a rigid tube are also conceivable.

[0010]The attachment of the tube element according to the invention for a
water drain to a pipe element as is present in the form of an inlet or
outlet tube in an air filter system can ensure with little effort that
the tube element is guided and protected both during assembly and also
during operation.

[0011]It is advantageous to use a tube element with a valve means. In this
way the interior of the tube element can be used as a collecting region
for the water which forms in the air filter.

[0012]Alternatively, a carrier element can be used not only for attaching
the tube element, but also for fixing the tube element on the pipe
element such that the tube element has an S-shaped segment or a loop.
Thus, without using a valve, it is possible for the tube element to be
closed against inflowing air by water which collects in the S-shaped
segment or in the loop in the above described manner according to the
siphon principle.

[0013]If the motor vehicle air filter system according to the invention is
intended for a vehicle, the motor vehicle can be produced more
efficiently with the same quality due to the enabled smooth assembly of
the motor vehicle air filter system.

[0014]For this purpose primarily an assembly method with the following
steps is advantageous: [0015]a) attachment of the tube element to a
pipe element with at least one carrier element, [0016]b) connection of
the pipe element to the air filter of the motor vehicle and [0017]c1)
simultaneous connection of the tube element to the air filter or
[0018]c2) simultaneous alignment of the tube element into a predetermined
position relative to the air filter and subsequent [0019]d2) connection
of the tube element to the air filter.

[0020]By the tube element, i.e., for example a hose for water drainage,
being attached to a pipe element which is to be mounted, such as, for
example, an outlet tube of the air filter, the tube element is moved
automatically into the position which has been predetermined for assembly
of the tube element by placing the pipe element in the engine compartment
and by connecting the pipe element to the motor vehicle air filter. The
sole further required step is the connection of the tube element to the
air filter. This further step can even be omitted when the tube element
has sufficient stiffness so that when the pipe element is assembled, the
tube element can be slipped onto the discharge of the air filter at the
same time. A suitably formed soft seal between the tube element and the
drain achieves a sealing action even when using very stiff tube elements.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 shows a part of the motor vehicle air filter system according
to the invention in a perspective and

[0022]FIG. 2 shows another embodiment of the tube device according to the
invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

[0023]The motor vehicle air filter system 10 according to the invention
which is shown in FIG. 1 has an outlet tube 12 for filtered air which
consists of an inherently stiff material. A drain hose 14 which is used
as a tube element for removing water is attached to the outlet tube 12.
In the region of the end of the drain hose 14 which points down in the
figure, in its interior there is a valve which is not shown in the figure
for sealing the drain hose against the entry of air. Secure retention of
the drain hose 14 on the outlet tube 12 is effected by two carrier
elements 16. Each of the carrier elements has two extensions between
which the drain hose 14 is snapped in. The outlet tube 12 is connected to
an air filter 18 on the bottom of its housing. When the outlet tube 12 is
connected to the air filter 18, the drain hose 14 which is attached to
the outlet tube 12 is automatically aligned such as to enable smooth
connection of the drain hose 14 to the drain 20 of the bottom of the
housing of the air filter 18 which is provided for this purpose.

[0024]The drain hose 14 is routed along the outlet tube 12 and is
positioned there both during assembly and also in operation in a defined
manner in the installation space. Kinking and an incorrect position of
the drain hose 14 in the space are thus prevented.

[0025]FIG. 2 shows a perspective of one embodiment of a tube device for
the motor vehicle air filter system according to the invention. A drain
tube 14 is connected to the outlet tube 12 by means of a retaining ring
16 which is used as the carrier element. The drain tube 14 is used to
drain water from the air filter. The retaining ring 16 is injected onto
the drain tube 14 here so that the retaining ring 16 and the drain tube
14 are materially joined to one another. On the opening which is intended
for connection of the drain tube 14 to an air filter there is a seal 22
which makes it possible to slip the drain tube 14 onto the drain fitting
of the air filter. The retaining ring 16 can likewise be fixed on the air
filter using a screw 24.

[0026]The embodiments of the tube devices of the motor vehicle air filter
system according to the invention which are shown in the two figures
enable smooth assembly of the tube device on an air filter by the outlet
tube 12 being connected to the air filter and thus the tube element 14
which is intended for discharging water being automatically aligned in
the case of the embodiment shown in FIG. 1 into a predetermined position
relative to the motor vehicle air filter 18 and, in the case of the
embodiment shown in FIG. 2, the drain tube 14 being slipped directly onto
the drain fitting at the same time.